Air Fortress FDS prototype

(The only April Fools joke in this post is that it’s entirely serious.)

We bought this a while ago and are only just now getting around to releasing it. Sorry.

This is a prototype of Air Fortress, a HAL Laboratory game for the Famicom/NES. But, uh… it’s a FDS disk. The game didn’t come out on the FDS.

Air Fortress seems to have been intended for the FDS originally; the conversion to Famicom cartridge was extremely sloppy, with duplicated graphics and wasted space abundant throughout the ROM. In any case, this prototype took the form of an FDS disk we bought from auction.

The disk is two sides, with side A containing the title screen and side B containing the game itself. There is no actual way to start the game from side A; you have to specifically start the FDS with side B inserted. (As far as the FDS knows, both sides are “side A”.)

The title screen has music that uses the extra FDS channels and sounds pretty good. It’s otherwise close to the final, except that pushing start doesn’t do anything and the story crawl is quite different, featuring a strange story that seems to reference… something. I lost my notes. At some point in the future I’ll edit it into this post when I find it again.

To start the game, you must turn off the FDS and insert the disk with side B up. Once the console boots, the disk immediately dumps you into a fortress; there is no side-scrolling shooter stage in this prototype. After defeating the core, the fortress goes dark, but the music does not change and the fortress never self-destructs. The escape hatch opens, but you can’t interact with your ship and are trapped inside forever. Or until you power the game off.

The map of the fortress itself does not match any of the fortresses in the final game and appears to be completely unique to this version. The large empty space is actually empty as well.  The map is fairly large, with a lot of looping paths and a few dead ends; if you take a direct route, you can effectively visit only about half of it.

You start with 1000 energy and 10 bombs. You can’t die; you will go down to 0 energy. If you take too much damage, your max energy will actually underflow, leaving you able to reach up to nearly 65,535. (In the gameplay video, we set the starting health/bombs to 9999 and 99 respectively to make it easier.) Some of the enemies in this game are far more aggressive than their final counterparts, firing bullets too quickly to be able to dodge. In some cases, it’s possible to be completely pinned into an elevator door from the constant barrage.

As for the prototype itself… the disk is not the original. The seller of this prototype, or someone who had it before them, created this copy by copying it over a different game. While the prototype itself seems to be authentic, this means that any data that might have been on the original disk ‘out of bounds’ is lost; instead, data from a different, unrelated game fills the rest.

There are still some leftovers, The code that remains looks like some sort of editor; the code abruptly starts and ends, though enough remains to create a mockup of what the screen would have looked like:

It is unknown what purpose this would have had, and no code that resembles it seems to exist anywhere else.

Thanks again to our Patreon supporters; without them we would not have acquired this prototype for release. Thank you for helping us preserve video game history.

Become a supporter of TCRF on Patreon

View and download the prototype on The Cutting Room Floor

Prototype Release: THQ’s unreleased Tetris DS

We bought and dumped a prototype (as well as a bunch of related documents), and we’re releasing them!

Keep reading

M.C. Kids and the unlimited lives secret

(This post was made with the support of our patrons. Thanks everyone! You can support us via tcrfwiki on Patreon)

This is a thing that BMF and I uncovered a bit ago, detailing an unintentionally very well-hidden secret.

M.C. Kids is an NES platformer game based around finding “cards” in levels to progress. Clearing stages in and of itself doesn’t allow you to progress beyond each “world” – you actually need to find certain numbers of cards. 

In addition to the usual world cards, there are also six secret cards laying around throughout the game. Once you’ve gotten every card, you can access a hidden area, “Ronald’s PuzzLeWoRlD”. (and yes, it’s really written like that.) This world has 3 stages, no cards, and no enemies – they’re just really difficult bonus levels.

Completing every stage will net you 10 extra lives when you go back and talk to Ronald at the start. At this point in the game, you’ve already cleared everything, and as hard as these stages are 10 lives isn’t really much of a reward. Turns out that there was supposed to be quite a bit more to it!

Every PuzzleWorld stage actually keeps track of how many of the arches (”coins”) you’ve collected, as well as the total number in each stage. If you can collect them all…

…nothing happens. Welp. The code checks if you’re in one of the three PuzzleWorld stages, and if you aren’t, it wipes the count. The problem is that this code happens to run during the end-of-stage high-five scene, and at that point you’re not in the level any more – it’s overridden by the cutscene. If not for that, the game would set a flag if you had gotten them all, one for each level.

But! There is a way to trigger it! Even though clearing the stage causes the bug to manifest… you can die. Dying will exit the stage, and the code still runs! So if you collect all of the arches and then off yourself, the flag will get set properly and you can trigger the secret. After doing this for each of the 3 stages, head back to Ronald and he’ll give you infinite lives…

On the way to talk to Ronald…

Woo! Look at all those lives!

…

Anyway, you’ll probably go play some stages after this, like the last one. If you’re not an expert, you might even die. Your count will stay at 99 the first time you lose a life.

After that, though, you start losing lives again! Turns out they weren’t so unlimited after all.

If you keep playing and doing poorly, you’ll eventually sink to 95 lives…

If you lose one more life here, instead of going back to the world map, you’ll be treated to another cutscene with Ronald at his secret house.

Your lives are again set to 99, and this time, they don’t decrement any more – you really do have unlimited lives for the rest of the game.

Oh Ronald, you card. Guess he really is a clown.

Anyway! Being as this is TCRF, some technical details follow.

The bits used for the arch/unlimited lives check live at $074B – the first three bits are for getting all arches in each stage, the next bit is for getting the fake unlimited lives, and once you get the 94-lives fakeout and full extra lives, everything is cleared and the fifth bit is set. (Basically, $07 -> $0F -> $10)

Completing a level via the “goal tape” sets the current level number to the cutscene, even if it doesn’t play, ruining the check for full arches. When this happens, the “is this a secret level” check fails, as it’s looking for $3B, $3C, or $3D, not the cutscene. When it finds that you’re not “in” those levels any more, it wipes your arch count, and the all-arches flag isn’t set. No bonus.

The most likely explanation is that this secret was added before the high-five cutscene was in, and was never updated, leaving it broken. It likely went undetected because of how difficult it is to pull off – PuzzleWorld is already hard enough to get to, let alone complete, and collecting all the arches – with no way to tell if you have all of them! – is a task only for absolute experts.

As far as we can tell, this has never been found or documented before, so it’s an entirely new discovery in a nearly 24 year old game.

No relation

A few games on the NES seem to have some interesting relationships to Nintendo’s flagship Super Mario Bros. game. For example, here’s Kid Kool, whose main character happens to share the exact same walk cycle as our hero Super Mario:

Even the pint-size version has a few distant cousins, shown here with Bomber Man and Challenger:

There are likely other games, too. The theory we had was that Mario was passed around as an example in a devkit, and some early games simply modified and reused some of the graphics. For the most part, though, nobody ever really noticed.

Shantae (GBC) stuff

Shantae has some labels and other stuff hidden out-of-bounds where you’re never supposed to see it, likely used by whoever was designing the maps. They were left in probably because many areas are all on the same “map” of sorts; you just can’t see them because of camera boundaries.

You can usually only see them by unlocking the camera, but several in the underground (caves) section are visible just by using debug mode.

Anyway, you’re probably interested in how to see these, or at least how to move around on your own.

Enable Debug Mode: On the title screen, press Left × 2, Right × 8, Left × 6, Right × 2, Left × 7, Right × 6, Left × 8. (The attentive among you will notice this is very close to WayForward’s phone number…)

You’ll be taken to a screen with “Start Normal Game” or “Start Debug Game”; picking the debug option will, when you start a new game on the next screen, start you with basically everything in the game (all dances, etc.).

To use free movement mode, Hold A and press Select, then press Select to exit out of it again. You’ll know it worked if Shantae looks like she’s falling, like the images below.

To unlock the camera, set the following memory addresses:

• Camera boundary, left: C9E9: 0000
  
• Camera boundary, up: C9EC: 0000
  
• Camera boundary, right: C9DD: 2000 (Little endian, 0020)
• Camera boundary, down: C9E1: 2000 (Little endian, 0020)

You’ll need to move away from the edge of the screen if it’s been pushed against the previous edge already… and several areas within the same map might use different tilesets, so they will look broken/garbled.

To automate unlocking the camera, use this script in VBA then press “Z”: https://github.com/Xkeeper0/emu-lua/blob/master/gameboy-vba/shantae.lua (will also show you the current player/camera coordinates so you don’t get lost).

For more information on cut/buried content in the game, see https://tcrf.net/Shantae . 

Valkyrie no Bouken: The “Zodiac Sign” bug

Namco(t) game Valkyrie no Bouken features a somewhat silly character creation menu, where you choose your character’s blood type, Zodiac sign, and color scheme. The color has no impact other than graphic; the blood type determines EXP requirements for each level; and finally, the Zodiac sign determines your starting HP and MP, and with it what spells you start the game with.

For blood types, one gives an EXP curve that’s much easier at the start but much harder later; the second gives a much flatter curve throughout; and the third one gives a hard start, but relaxes the curve greatly later on, paying off with a lower requirement for later levels. The final blood type just gives you a random curve decided every time you level.

There are twelve Zodiac signs, and internally these are divided into four groups:

There is a big variation between the first three, but the last one is only one point different from the group before it.

It turns out that this is due to a bug in the programming! The final group is actually supposed to randomly assign you max HP/MP – HP is chosen from 32-64, and MP is 96 - HP, for a total of 96 every time.

However, as part of the character creation routine, the game wipes the address that stores the current random number, so every time the game generates a character, it will always get the same result – in this case, a random value of 1, giving (32 HP + 1) = 33 HP and (96 - 33) = 63 MP.

Given that the relation of Zodiac sign to starting HP/MP is not made obvious (nor blood type to EXP curve), it is plausible that this bug was never caught during testing, since the impact on the game is pretty low.

I might make a patch to fix this later, depending on how far I get with the disassembly of this game…